The present invention relates to a vibration-generating device used in a game controller, a vibration controller, or a wireless device and to a method for mounting a weight to the vibration-generating device.
Some conventional weights include a body 11 of a semicircular columnar section having a U-groove 4 formed at the center in a diametric direction that receives a shaft 3. On both sides of the U-groove 4 linear projections 13a and 13b extend upwardly.
When the weight 10 is mounted on the shaft 3, the shaft 3 is inserted into the U-groove 4. A support block 1 supports the weight 10. A supporting surface within the support block 1 that has the same configuration as a perimeter of the weight 10 that supports a flat portion of the weight 10 at a level position.
A pressing member 12 having a recess 12a shown in triangular cross-section is lowered until the weight 10 is fastened to the shaft 3. The surface area of the recess 12a near the end of the pressing member 12 is smaller than the surface area of the projections 13a and 13b and the space that separates the projections 13a and 13b. The recess 12a of the pressing member 12 is pressed into contact with the edges of the projections 13a and 13b which bends the projections 13a and 13b inwardly as shown by the R and L arrows, which caulks the weight 10 to the shaft 3.
The conventional method shown in FIGS. 8 and 9 can be used when the weight 10 is produced of a relatively soft material such as copper. However, when the weight 10 is made of a relatively hard material such as iron, a much larger pressure is needed to mount the weight 10 to the shaft 3.
If an insufficient force is applied to the weight 10 by a conventional method, the weight 10 can be easily removed from the shaft 3 with a relatively small force. If the weight 10 is not properly secured to the shaft, the weight 10 can fall off the shaft 3 and produce an undesired noise or impair device operation.
As shown in FIGS. 8 and 9, a portion of an inside wall of the U-groove 4 is straight, and therefore, a large force can be needed to deform the projections 13a and 13b into a curved surface that encloses a portion of the shaft 3. If an insufficient force is applied, the projections 13a and 13b may not sufficiently enclose a portion of the shaft 3.
In a preferred vibration-generating device, a weight has a shaft insertion hole of an approximately semicircular section that is partially open near the center of an upper edge of the weight. Recesses for caulking are located near the open portion of the insertion hole. With a shaft inserted within the insertion hole, a pressure is applied to at least one of the recesses or to an open-end side which fastens the shaft to the weight.
By the above-preferred method, the weight is firmly attached to the shaft with less pressure than the pressure used in some conventional methods. Furthermore, cost reduction can be realized when the weight is produced of a low-cost material such as iron. Furthermore, since some iron can be shaped to a desired accuracy and can be less likely to deform, the weight is less likely to fall off the shaft. Preferably, the insertion hole encloses more than about one-half of a cross-sectional circumference of the shaft. In some presently preferred embodiments, the insertion hole encloses about three quarters of the cross-sectional circumference of the shaft.
Preferably, the weight can be held in surface contact with the shaft. That is, the inner surface of the insertion hole is preferably about the same shape as the outer surface of the shaft. Preferably, a portion of the inner surface of the insertion hole contacts an outer curved surface of the shaft when the weight is secured to the shaft. Therefore, in comparison with some conventional weights having a U-groove, the presently preferred weight can be mounted more firmly to the shaft. Preferably a clearance between the inner surface of the insertion hole and the outer surface of the shaft is greater than or equal to about {fraction (1/100)} mm and less than or equal to about {fraction (8/100)} mm, and more preferably, greater than or equal to about {fraction (3/100)} mm and less than or equal to about {fraction (5/100)} mm. Preferably, the thickness between the recess and the inside wall surface of the insertion hole is between about 0.5 to less than about 1.0 times the shaft diameter.
The presently preferred method of mounting the weight to the vibration-generating device includes a process that inserts a weight onto the shaft, a process that supports the weight, and a process that applies a pressure to fasten the weight to the shaft. In the presently preferred method, the weight is of an approximately semicircular columnar section that has a shaft insertion hole partly open near the center of an upper edge of the weight. Preferably, at least one recess is positioned near the open portion of the insertion hole. After the shaft is inserted into the insertion hole, the weight is supported in an inclined position and a pressure is applied to one of the recesses or to the open end side near that recess by a curved end of a single ended pressing member. Preferably, the curvature of the curved end of the single ended pressing member matches or substantially matches the curvature of the concave shaped recesses. Preferably, the single ended pressing member exerts a pressure on the weight offset or distant from a rotational axis of the shaft.
According to the presently preferred method, the weight is mounted while supported by a support member. In this preferred embodiment, the support member supports the weight such that an upper edge portion of the weight is inclined relative to a horizontal plane or a horizontal surface of the support member. A pressure is applied to the supported weight by the single ended pressing member. In this preferred embodiment, the pressing member presses at least one of the recesses adjacent to the insertion hole or the open-end side near that recess. In this preferred embodiment, the pressure preferably conforms a portion of the inner surface of the insertion hole to an outer surface of the shaft. Preferably, the single ended pressing member applies a pressure in a substantially vertical direction that is offset or distant from the rotational axis of the shaft.